And frank hammond



U ITE Sm'nss PATENT OFFICE WILLIAM ,NELSON REDDOUT, OF, RUSHV'ILLE, NEW YORK. Assienoa'ro ARTHUR B. BURTIS, F CLEVELAND, OHIO, AND FRANK HAMMOND, or

PHELPS, YORK.

com: FOR CASTING.

srncmrcanon formingpart of Letters Patent Nb. 418,750, dated January 7,1890.

. Applioatlonfilosl August 27, um.- Ber-kilo. 248,075., (No model) To all whom it may concern.- Be it known that I, WILLIAM NELSON RED DOUT, a citizen of the United States. of

re cores for producing castings with cavities,

orifices, depressions, &c.

The object of my invention-is to obtain a core, either solid or hollow, of a permanent or indestructible character-that is to say, a

core which can be readily drawn without injury thereto, and can be repeatedly used, and one which will give to thecasting a finished surface, that facilitates the drawing of the core and precludes the necessity for subsequent reaming or'dressing, and which leaves the metal of the casting in a condition to be easily tapped or dressed if the same is desired. To this end the invention, generally stated,

consists in a core composed of. asbestus with- 2 5 out admixture of other matter, whereby a dense, polished, uniform, refractory, nonscaling or non-shelling, non-cracking, permanent core is produced.

Heretofore, so far as I am aware, ashe st 11 s,.

wherever employed in this character of devices, has been used largely as a binder to hold together frangible or 'friable. material mixed therewith-such as graphite, kaolin, clay, mica, and like refractory material-and 3 5 with a cement-such as shellac, pitch, silicate of soda, or its equivalentthe whole mass be ing molded or dried, either with or without pressure, and productive of what may be termed a composition or combination 4ocore. Inthe first place, such cores are not what I term permanent cores, as they are destroyed in their removal from the casting and cannot be repeatedly used; they are durable only in the sense that they will stand the pressure of the molten metal in the.

' operation of casting; secondly, being of two ormore difierent materials, they are unequally ,aifected by the molten metal, and will warp,

crack, and shell, leaving the metal of diffen (preferably-hydrostatic pressure) in a suitaentcharacter at dili'erent points and the casting as rough and unfinished as-the old and well-known sand cores, necessitating first the destruction of the core for its removal, and after that the reaming or dressing of the a casting. Such cores cannot-be drawn so as to 5 5 remain .in condition for further use-first, owing to their composition, and, second, owing to the character of the casting.

I do not claim composition or combination cores of the classor. character specified of which ashestus is only an element.

- Having thus indicated and-acknowledged what has heretofore been done, I .will now proceed to describe'specifically the best manner? known to me of applying my invention, I I take the asbestus first as it is mined selecting by preference that which is mostfree from admixture with si'lica,lime, or other ex traueous matter, as the less foreign matter present the better will be the-result. The 7o asbestus is' shredded or reduced to a fine flocculent mass, and, if-desired, may be. washed and purified by any' of the several well-known methods. it is then reduced-to an adhesive condition or slightly plastic mass by adding thereto a vehicle which can be readily expelledtherefromesuch as water or lirqseed-oil-and is subject to. high pressure ble mold, and, preferably while under press-- me, it is subjected to heat suificient to vexpel the water, linseed-oil, or other vehicle used. to render the mass plastic, or to expel as much as possible thereof and reducethe rest toan in noxious matter, which will constitutea very insignificant and I inappreciable portion of the core,.leaving the core for all practical pure poses with exterior surfaces of pureasbestus,

A core produced substantially o'r entirelyof the-material as herein specifiedwill have a-perfectly hard smooth surface, and its density or compactness will depend to a certain'extent-ou the amount of pressure exerted in its formation. Its surface, being of the same smooth and uniform finish as metal, 5 will impart a like surface to the casting, which enables-the .core to be readily drawn and" leaves it (the core) in'condition for repeated use. Unlike composition cores, it will not scale,shrink, or crack, and therefore, if care has been taken in forming the core, the casting, when the core is drawn, is ready for immediate use, as the cavity therein is' perfect and smoothand an exactrcproduction of the core; hence there is great saving of time'arzd labor, not only in the repeated use of the core, but also in the reduction of labor required in fitting or finishing up the casting. Furthermore, while capable of and possessing the smooth surface of a metal core, it is unlike metal, sand, or composition cores, in that it does not harden or otherwise affect the character of the metal cast, leaving the surface which was in contact with the core uniformly smooth, tough, and soft throughout and,

readily workable-a great advantage if tapping, reaming, boring, or subsequenttreatment of the casting is desired.

The invention asabove described is applicableto the manufacture of any shape or character of cores desired, whether solid or p'art-ible, and can be readily applied by the skilled core-maker without other instruction thairthat given.

Having thus described the nature and advantages of my invention, what I claim, and desire to secure by Letters Patent, is-

1. A core for casting, said core having a smooth hard exterior surface composed entirely of asbestus, substantially as specified.

2. A core for casting, said core-having a smooth dense surface of a polished, uniform, non-scaling character, composed entirely of condensed and compacted asbestus,subst'1n tially as and for the purposes specified.

In testimony whereof I affix my signature in presence of two witnesses.

WILLIAM NELSON REDDOU'P.

Vvitnesses:

S. S. CATLIrt, W.'M. TAYLOR. 

